i approve, Sir Rickety.
looks like u and ur oponent play each other often or have cuz both of ya'll exert a specific style no more complex than needed be....plus this is mario vs. doc, so with those things in mind, i think any advice should be taken w/ a grain of salt, since this is not like a tournament match against a high tier from a random good player.
but yea..anyway, i think ur doc is pretty sweet.
i like the sidestep-turnaround-d.smash usage and the defensive ground game.
One thing i could think of, is the overuse of 'Dash-reverse WD'. I think its a great tool, but it may further benefit you if u mixed it up w/ other feints as well, such as an empty SH to reverse WD, and...well..u don't shuffle offense all that much to begin with.
I'd like to see more sex kick shuffles into Jabs. they work pretty well versus mario if u can pull it smooth enough to avoid the shield grab.
Maybe once you get ur oponent paranoid of shuffles, some empty shuffles to reverse WDs would work well, on top of some empty shuffles to grab.
Iunno...i'm just making crap up that u could experiment w/ and just find what works for u, cuz just from my own experience, i used to dash-reverse-WD too much, and eventually it just kept getting me in trouble (it still does, sometimes, lol)
You don't really use D.air. I think its underrated move. I find full jumping over the oponent while D.Airing (to guard urself as u pass to the other side of them) and falling w/ b.air/etc, to be an odd, cool trick to throw out once in a while, as well as in close quarters to pass through a shield into some jabs, or while recovering from the edge.
i think i just recapped what others have been saying, so i hope its not redundant at this point, but anyway..yea, i enjoyed watching ur doc. makes me wish i could get some new vids up (no cam, anymore) :/